Mass spectrometry is a method of separating ions based on the mass-to-charge ratio (m/z) of molecular ions in vacuum, capable of separating and detecting ions with high sensitivity and high accuracy. The mass spectrometry technology is generally used for detectors in a liquid chromatograph (hereafter “LC”) or gas chromatograph (hereafter “GC”), often involving an analysis technique called liquid chromatography/mass spectrometry (hereafter “LC/MS”) or gas chromatography/mass spectrometry (hereafter “GC/MS”). In recent years, progress has been made in the development of tandem mass spectrometry which decomposes an ion as the object of measurement and measures the decomposed ion, and high-resolution mass spectrometers such as a time-of-flight mass spectrometer and a Fourier transform mass spectrometer. These technologies are becoming widely available in biotechnology and medical fields in particular.
Meanwhile, ion mobility spectrometry (hereafter “IMS”) is a method for ion separation in a gas phase under atmospheric pressure. Ion mobility spectrometry separates ions by utilizing the difference in the speed of ion movement in a gas phase due to difference in ion structure from one ion to another. Thus, ion mobility spectrometry is capable of separation in principle even between different kinds of ions having the same m/z. Because ion mobility spectrometry is a different separation method from mass spectrometry, a measurement method combining mass spectrometry and ion mobility spectrometry has been reported. An example of ion mobility spectrometry is a field asymmetric waveform ion mobility separation device (field asymmetric waveform ion mobility spectrometry; hereafter “FAIMS”).